The waves may have retreated but victims of the tsunami face a surge of amputations as superbugs hit Samoa's biggest hospital.

Medics have warned that hundreds of victims of the disaster are risking limb removal from festering wounds that have stopped responding to antibiotics.

Many others have "tsunami lung" after being forced to swallow polluted seawater under high pressure, and have gone on to develop pneumonia.

"The situation is not good, it's actually very nasty considering most of these patients were otherwise healthy young and middle-aged people," said Teuila Percival, a New Zealand specialist who worked in the emergency medical team at the main hospital in the capital, Apia.

Samoa did not have the processes in place or the range of alternative antibiotics to cope with such an onslaught, Dr Percival said.